The Desertification Study And Environmental Quality Assessment In Middle Inner Mongolia Region

Desertification and global change, the protection of the variety of the species, theprevention and fathering technique of the desertification, and the supervision andevaluation technique, all have become the core and hotspot in the world study. Thesurvey about the desertification refers to the investigation on the land type, area,distribution, cause and harm of the desertification, and the study about the variety andfunction of the desertification prevention methods, which are the basis for thedesertification prevention. As well, the survey includes the investigation on all kindsof the resources in the desertification land and their distribution, which can be used asthe basis for the regional sustainable development. The survey also offers the theorybasis for the constitution of the desertification prevention layout and of the methodsof the fathering, and meanwhile for the supervision and evaluation of theenvironment.This paper is about Middle Inner Mongolia region, which is a typical region ofdesertification. The structure of the decision tree and the corresponding position ofeach targets are determined according to the desertification land classification.According to the spectrum-reflecting characteristic of targets and the integratedfeature of TM and ETM+ image data, proper identifying and extracting methods areapplied. So the potency of the remote sensing data is maximized. From the multi-bandand multi-time TM and ETM+ remote sensing data, the spectrum-reflecting properties,the Soil-Adjusted Vegetation Index (SAVI), Soil Brightness Index (TC1), andMoisture Index(MI) are extracted. And these indexes are used to distinguishing andclassifying the different land types. The result shows the Decision Tree andMulti-layer method is efficient to decrease the intrusion of the extra information in thepixel identification and make the targets definite. Through Image Algebra Detectionmethod and Visual Interpretation method, the changes of the desertification from 1990to 2000 will be collected, and the evolvement rule of desertification in the study areawill be analyzed. Finally, with the technology of GIS, the analysis of the ecologicalenvironment quality changes and climate factors changes reveals that the main factorsto influence the environmental changes are precipitation and evaporation(desiccation).